In this application we propose to design, develop and test novel MRI compatible Micro Magnetic Brain Stimulation "MMBS" methods in awake behaving monkeys. These devices will be implanted in the frontal eye field (FEF) of non-human primates. Magnetic micro-stimulation of FEF is expected to elicit spatially-specific behavioral responses in terms of saccadic eye movements and to modulate visually-driven activity in occipital cortex. Compared to traditional electrical microstimulation (EM), 5MBS can be used to increase (single pulse stimulation) or decrease (repeated theta-burst stimulation) excitability of neuronal tissue. Hence we can investigate the causal functional and behavioral consequences of nearly identical focal activations and de-activations of small portions of the FEF. Moreover, as the probes can be completely insulated from the brain tissue, we expect to record artifact-free neuronal activity in functionally connected sites during 5MBS. Finally, as Transcranial Magnetic Stimulation (TMS) is presently the method of choice to investigate causal functional interactions across brain regions in the human, 5MBS will bridge the gap between human and monkey effective connectivity studies. PUBLIC HEALTH RELEVANCE: The proposed research aims at the stimulation of the Frontal Eye Field in Monkeys with a microscopic magnetic field which allows simultaneous artifact-free electrophysiological recordings during stimulation. The development of such novel technology will result in significant advances in understanding causal and behavioral and functional consequences throughout the brain induced by focal increased and decreased activity of the FEF.